Bile salt-dependent lipase explained

Bile salt-dependent lipase (or BSDL), also known as carboxyl ester lipase (or CEL) is an enzyme produced by the adult pancreas and aids in the digestion of fats. Bile salt-stimulated lipase (or BSSL) is an equivalent enzyme found within breast milk. BSDL has been found in the pancreatic secretions of all species in which it has been looked for. BSSL, originally discovered in the milk of humans and various other primates, has since been found in the milk of many animals including dogs, cats, rats, and rabbits.^[1]

Enzymatic activity

More than 95% of the fat present in human milk and in infant formulas is in the form of triacylglycerols (TG).^[2] In adults, TGs are thought to be broken down or hydrolyzed mainly by the colipase-dependent lipase (CDL) enzyme. In the newborn, CDL activity in the duodenum is lower than in adults.^[2]

Both BSDL and BSSL have a broad substrate specificity and, like CDL, are capable of hydrolyzing triacylglycerides (in addition to phospholipids, esters of cholesterol, and lipid-soluble vitamins). In particular, they can hydrolyze esters of the essential fatty acids (n-3 and n-6 PUFAs) and DHA.^[3] BSDL production in the newborn pancreas is quite low when compared with production in the mammary gland or adult pancreas.^[4]

However, newborn infants absorb lipids relatively well, considering the low level of CDL and BSDL they produce. This observation has led to the suggestion that BSDL produced by lactating mammary gland and present within milk, may compensate for the low levels of other TG-digesting enzymes and aid newborns in lipid absorption.The importance of BSSL in breast milk for the preterm infant nutrition was suggested at 2007.^[5] It was also directly shown recently.^[6]

Further reading

• Kumar BV, Aleman-Gomez JA, Colwell N . Structure of the human pancreatic cholesterol esterase gene. . Biochemistry . 31 . 26 . 6077–81 . 1992 . 1627550 . 10.1021/bi00141a017 . etal.
• Lidberg U, Nilsson J, Strömberg K . Genomic organization, sequence analysis, and chromosomal localization of the human carboxyl ester lipase (CEL) gene and a CEL-like (CELL) gene. . Genomics . 13 . 3 . 630–40 . 1992 . 1639390 . 10.1016/0888-7543(92)90134-E . etal.
• Taylor AK, Zambaux JL, Klisak I . Carboxyl ester lipase: a highly polymorphic locus on human chromosome 9qter. . Genomics . 10 . 2 . 425–31 . 1991 . 1676983 . 10.1016/0888-7543(91)90328-C . etal.
• Nilsson J, Bläckberg L, Carlsson P . cDNA cloning of human-milk bile-salt-stimulated lipase and evidence for its identity to pancreatic carboxylic ester hydrolase. . Eur. J. Biochem. . 192 . 2 . 543–50 . 1990 . 1698625 . 10.1111/j.1432-1033.1990.tb19259.x . etal. free .
• Lindström MB, Persson J, Thurn L, Borgström B . Effect of pancreatic phospholipase A2 and gastric lipase on the action of pancreatic carboxyl ester lipase against lipid substrates in vitro. . Biochim. Biophys. Acta . 1084 . 2 . 194–7 . 1991 . 1854805 . 10.1016/0005-2760(91)90220-C.
• Baba T, Downs D, Jackson KW . Structure of human milk bile salt activated lipase. . Biochemistry . 30 . 2 . 500–10 . 1991 . 1988041 . 10.1021/bi00216a028 . etal.
• Christie DL, Cleverly DR, O'Connor CJ . Human milk bile-salt stimulated lipase. Sequence similarity with rat lysophospholipase and homology with the active site region of cholinesterases. . FEBS Lett. . 278 . 2 . 190–4 . 1991 . 1991511 . 10.1016/0014-5793(91)80114-I . 28123400 . free .
• Reue K, Zambaux J, Wong H . cDNA cloning of carboxyl ester lipase from human pancreas reveals a unique proline-rich repeat unit. . J. Lipid Res. . 32 . 2 . 267–76 . 1991 . 10.1016/S0022-2275(20)42088-7 . 2066663 . etal. free .
• Hui DY, Kissel JA . Sequence identity between human pancreatic cholesterol esterase and bile salt-stimulated milk lipase. . FEBS Lett. . 276 . 1–2 . 131–4 . 1991 . 2265692 . 10.1016/0014-5793(90)80525-N . 10716446 .
• Escribano MJ, Imperial S . Purification and molecular characterization of FAP, a feto-acinar protein associated with the differentiation of human pancreas. . J. Biol. Chem. . 264 . 36 . 21865–71 . 1990 . 10.1016/S0021-9258(20)88264-7 . 2600091 . free .
• Erlanson-Albertsson C, Sternby B, Johannesson U . The interaction between human pancreatic carboxylester hydrolase (bile-salt-stimulated lipase of human milk) and lactoferrin. . Biochim. Biophys. Acta . 829 . 2 . 282–7 . 1985 . 3995055 . 10.1016/0167-4838(85)90199-2.
• Chekhranova MK, Il'ina EN, Shuvalova ER . [Cloning, determination of primary structure, and expression of the C-terminal segment of human cholesterol-esterase/lipase, containing the antigenic determinant of the protein, in Escherichia coli] . Mol. Biol. (Mosk.) . 28 . 2 . 464–7 . 1994 . 7514266 . etal.
• Roudani S, Miralles F, Margotat A . Bile salt-dependent lipase transcripts in human fetal tissues. . Biochim. Biophys. Acta . 1264 . 1 . 141–50 . 1995 . 7578248 . 10.1016/0167-4781(95)00141-3. etal.
• Bruneau N, de la Porte PL, Sbarra V, Lombardo D . Association of bile-salt-dependent lipase with membranes of human pancreatic microsomes. . Eur. J. Biochem. . 233 . 1 . 209–18 . 1995 . 7588748 . 10.1111/j.1432-1033.1995.209_1.x . free .
• Wang CS, Dashti A, Jackson KW . Isolation and characterization of human milk bile salt-activated lipase C-tail fragment. . Biochemistry . 34 . 33 . 10639–44 . 1995 . 7654718 . 10.1021/bi00033a039 . etal.
• Nilsson J, Hellquist M, Bjursell G . The human carboxyl ester lipase-like (CELL) gene is ubiquitously expressed and contains a hypervariable region. . Genomics . 17 . 2 . 416–22 . 1993 . 7691717 . 10.1006/geno.1993.1341 .
• Bruneau N, Lombardo D . Chaperone function of a Grp 94-related protein for folding and transport of the pancreatic bile salt-dependent lipase. . J. Biol. Chem. . 270 . 22 . 13524–33 . 1995 . 7768954 . 10.1074/jbc.270.22.13524 . free .
• Mas E, Abouakil N, Roudani S . Human fetoacinar pancreatic protein: an oncofetal glycoform of the normally secreted pancreatic bile-salt-dependent lipase. . Biochem. J. . 289 . 2. 609–15 . 1993 . 8424803 . 10.1042/bj2890609. 1132213. etal.
• Shamir R, Johnson WJ, Morlock-Fitzpatrick K . Pancreatic carboxyl ester lipase: a circulating enzyme that modifies normal and oxidized lipoproteins in vitro. . J. Clin. Invest. . 97 . 7 . 1696–704 . 1996 . 8601635 . 10.1172/JCI118596 . 507234. etal.
• Landberg E, Påhlsson P, Krotkiewski H . Glycosylation of bile-salt-stimulated lipase from human milk: comparison of native and recombinant forms. . Arch. Biochem. Biophys. . 344 . 1 . 94–102 . 1997 . 9244386 . 10.1006/abbi.1997.0188 . etal.

Notes and References

1. Swan JS, Hoffman MM . Two forms of human milk bile-salt-stimulated lipase . Biochem. J. . 1992 . 283 . 1 . 119–122 . 10.1042/bj2830119 . 1567358 . 1131002. etal.
2. Lombardo, D. . Bile salt-dependent lipase: its pathophysiological implications . Biochimica et Biophysica Acta . 2001 . 1533 . 1 . 1–28 . 11514232 . 10.1016/S1388-1981(01)00130-5.
3. • Murasugi A, Asami Y, Mera-Kikuchi Y . Production of recombinant human bile-salt-stimulated lipase in Pichia pastoris . Protein Expression and Purification . 23 . 2 . 282–288 . 2001 . 11676603 . 10.1006/prep.2001.1509.
4. Sbarra V, Bruneau N . Molecular cloning of the bile salt-dependent lipase of ferret lactating mammary gland: an overview of functional residues . Biochimica et Biophysica Acta . 1998 . 1393 . 1 . 80–89 . 9714751 . 10.1016/S0005-2760(98)00067-8. etal. free .
5. Andersson Y, Sävman K . Pasteurization of mother's own milk reduces fat absorption and growth in preterm infants . Acta Paediatrica . 2007 . 96 . 10 . 1445–1449 . 17714541 . 10.1111/j.1651-2227.2007.00450.x. 995002 . etal.
6. Web site: Maggio, L. . Bellagamba, M. . etal . A prospective, randomized, double-blind crossover study comparing rhBSSL (recombinant human Bile Salt Stimulated Lipase) and placebo added to infant formula during one week of treatment in preterm infants born before 32 weeks of gestational age: preliminary results . Swedish Orphan Biovitrum .